Flotation of ores



alkaline salt, an alka 1 or botht Patented May 1,- 192a *uw v' STATES. PATrE M j wB- GEORGE aomswoi n, ans-Ann our 1; summit, or nur'rn,.nonmma.

rnomn'non or aims.

Ito Drawing.

.Tliis invention relates to the eoncentra tion of ores by flotation, and, more articularly, to thediflerential flotation 1o 'mixed sulfide ores.' The invention has for its ob 5 ject the provision of an impro vedmethod of concentrating mixed or. complex sulfide ores by differential flotation. larly, the invention aims to provide an improved methodof concentrating by differential flotation a mixed or-complexsulfide ore containing either, or both lead or copper sulfides associated with eithegor" both zinc" or iron sulfides.

Our present invention involves. treatin' the mixed orico'mplexsulfide ore, reduce to a flotable size, .With a halogen, suph as chlorine, bromine or iodine, either inneutral (that is, non-acid) solution, or in eon'u'nc tion with an alkaline a ent'such as ana kali,

i earth salt or by- I The.- lead or fcop er, may be floated as a .pr'imary'pr' I not and the zinc as-a. secondary'product.- The iron is inhibited froin floatlng and-remains drox'ide, and-the like.

1? with the tailing. If desired,;a"iron concenr iron" sulfide-is inhibitedI In general, the ore isgroundtoithe :de- 40 sired size in a ball-,millin the'presence of a halogen alone or together with an appro f ,priate alkaline agent. manyjinstances, improved results are 'obtjai'nedfby the. addi tion .offlzinc sulfate." I

is thereafter subjected to a flotation opera tion in the pre'senc'e f'an oil, or other ap propriate flotation agent, whereby 'a froth per, or'bo'th. The oil, or other appropriate 0 flotation agent,'may be addedatthe ball,

mill, or at the flotation machine,*or at an intermediate point, according. tothecharac- II I teristics-of the ore and flotation "agent. .Af-

ter removal of the lead or copper, or both,

' I ap ncaammea llamas,

More. partiou sulfide; The iron is and remalns with the tailing.

I from one another,

. in; a tank or readiness I passed to aflotation machine of a suitable I .type, where,af; ter the addition of oilor other Y agents may be addedtot in accordance The thus, treated Q f I I I I I j in securing a lead is formed contalnmg most of the lead orecop- 1924. serial na'asaaso;

an appropriate amount of an. alkaline or a halogen, or a halogen and an agent, is. added, proved results may 'be'obtained by the additlon of copper sulfate with one ormore of the other reagents. then subjected to another: flotation operation to form afroth containing most'of the zinc.

inhib1ted from floating If the ore is already of such fineness that to a time treatment in the presence of a halogen alone, kaline age'nt,fwith or without zine sulfate, and so constructed as to give the pulp t e necessary treatment." The pulp is now in for difierential separation, and is agent, alkaline In certain instances, lm-

The remaining ore is or in conjunction with an alother'container large enou h appropriate. flotation agent, a froth contain :ing the lead or copper the flotationof thejzine The further treatment as previously described I I I e ulpat any point preceding the flotation of t e thatthe pulp and reagents time to interact.

our investi ber of theha ogen group may be employed practice, eitherbromine, may In conjunction with a with the invention; that is, in.

I chlorine, or iodine be employed with finally good results. hja ogen, we may em or both, isproduced; and iron is inhibited; ot thepulp andsubsequent flotation of .the zinc is v conducted although the rezinc, provided have .sulliclent' ations indicate'that menii ploy an alkaline agent, such'as an alkali."an

"alkaline salt-,- an alkali "earth salt or hyfThe particular alka droxide, and the like.

lineagent employed is determined the nature of vthegore'fiis willlb e stood by. the. art, In

treating some ores,'it is bination with the other reagents, as it aids product low'in zinc. I The practice of the invention will be further illustrated by'the followingexamples:

I 11. *IOOOgrams of ore (through which was'added 50000.01? water, bromine- 1 .0 lb. per ton, I per ton, and zinc, sulfate-0.5 lb. per ton of sodium biearbonat'e3.0 lbs.-

' advantageous ploy zinc. s 'ulfatein comll) mesh) to m;

ore, were ground until the ore minerals (sul-f the grains of the'eomponent sulfides are free the ore pulp is subjected p fides) were free and of a size suitable for flotation. The pulp was then d1luted-. to

about 4 parts of water to 1 part of ore .by weight and transferred to a laboratory flotation machine, 0.3'lb. of Barrett No. 4 oil added, and the resultant froth, containing the lead (galena) removed; 1.0 lb. of canstic soda and 1.0 lb. of copper sulfate were added to the pulp, and allowed 'to mix and reactwith the pulp for two minutes. A

froth containing the zinc formed upon the addition of 0.8 lb. of a coal tar. creosote and 0.1 lb. of a steam distilled pine oil, and was removed. Th1s froth was given one cleaning in the same machine, but without further addition of oil or other reagents, resulting in a zinc concentrate and a zinc cleaner tailing or middling product. The results of-this run areindicated in "the following tabulation PM Assay Per cent recovery cent Product g Pert Pert Iert V F Z I b can con can 9 11 weight Fe Zn Pb .0 0. e 15. 2' s. 0 100. 0 100. o 100. .9 3.6 10.6 55.0 5.9 7.6 69. 24.9 4. 7 49.1 7.9 17. 7 80.5 22. Zn m1dd1ing.... 9. 3 9.1 13. 4 2. 0 12. 9 8. 2 2. Teuing 54.9 7. 0 1. o 0. s 63. 2 9. 5 5.

Total"..- 100.0 99.7 99. 9 99.

2. The same procedure as in Example No.

1, but in which 1.0 lb. of iodine per ton of ore is substituted for bromine 5. 1000 grams of ore were ground to the. required finenesswith 500 cc. of water, 1.0

lb. of chlorine, and 1.2 lbs. of sodium hydroxide er ton of ore. The pulp was then dilute to about 4 parts of water to 1 part of ore by flotation machine. After the addition of 0.3

lb. of Barrett No.4 oil (per ton of ore), a

froth was produced which contained the lead (galena); then 1.0 lb. of sodium hydroxide per tonof ore was placed in the pulp, and after a time interval of two minutes, 0.8 lb.

of coal tar creosote and 0.1 lb. of pineoilwere added, and a froth containing the zinc (sphalerite) produced. The iron remained in the tailing.

PM Assay Per cent recovery cent f g Pert Iert Part F z Pb een een can 9 n Fe Zn Pb 14. 3 7. 9 100. 0 100. 0 100. 0 16. 2 50. 6 6. 4 14. 1 79. 4 50.8 6.0. -14.8 70.0 14.9 23. 0 3. 2 l5. 2 12. 5 3. 2 0. s 0. 9 ea. 7 3.; 2:2 100. 1 9 99. 9 99. 1

3. The same procedure as in Example No.

1, but in which 1.0 lb. of chlorine is substi-' tuted for the bromine, and 310 lbs. of sodium carbonate for the bicarbonate:

A Per ssay Per cent recovery cent Product natal. t t Part- I: Pb

- can can can 0 n I (9 Fe Zn r1.

100.0 7.7 11.2 5.7 100.0 100.0 100.0 8.4 6.2 14.0 50.6 6.8 10.5 74.6 14. 5 6. 9 48. 7 6. 0- 13.0 63. 0 15. 2 H 9.0 14.0 24.0 9.0 10.4 19.3 4.7 Ta1l1ng---'.-.-.. 68.1 7.2 1.2 0.5 63.6 7.3 6.0 Total"-.. 100.0 99.8 100.1 100.5

4. The same mechanical procedure as in Example No; 1. The reagents-used are 3.0

. the desi Assay Per cent recovery Pro can Product tote! Per Per Per 7 weight cent cent cent Fe Zn- Pb 1 Fe Zn Pb 8811. 100. 0 8. 2 12. 8 8. 7 111110 100. 0 100. 0 Pb R. cone 14.6 4.0 18.4 45.3 Y 7.2 21.0 75.8 Zn conc..-. 10.2 5. 2 48.6 7. 7 10.3 61. 5 14.4 z 0110011 1 9.1 a9 1.9 1.0 04.5 5.0 I 0.9 Total"--. 405 s2. 0 9s. 5 91.1

6. 1000 grams of ore (through 10 mesh) were ground to the. required fineness with 500 cc. of water, and bromine equivalent to 1.0 lb. per ton of ore. The pulp was diluted as before and then passed to a flotation machine. Upon the addition of 0.4- lb. of Bar? weight and placed in a laboratory rett No. 4.011 r-ton of ore), a froth containing the lea was produced; the zinc and iron remaining 'in the tailing. A.zin c concentrate is not shown, but may be made in the same manner RS111 preceding tests.

Assay Per cent recovery Prof A can n i motel Per Per Per I weiht cent cent cent Fe Zn- Pb.

Fe Zn Pb 6.32 14.07 6.61 100.0 100.0 1(X).0 3.5 9.6 52.0 5.1- 6.9 72.5 6.6 14.4 2.0 94.9 93.1 27.5 'r0m1-..:. 10110 100.0 100.0 100.0

, -7. 1000' rams of an ore were round' to .finenes in a. ball mil with L 1115.01 sodium carbonate, 1.0 lb. of zinc sul- Barrett No. 4 oil. The greater portion of fate, and 1.0 lb. of chlorine per ton of ore,

and 500 cc. of water. [The ulpwas diluted as before and'then place in a flotation chlor ne per ton of ore was added. A- froth rich in'zinc and oil. The r'emainderof'the zinc was' fl0ated and removed 'by the addition. of0.5 lb/of theiron ,remained in the tailing; The zinc rougher concentratewas' cleaned'on e, formj mg flZlIlO concentrate and a zinc middling.-

I Assay 7 Per cent recovery can 0 i I 1 Pmduct total I For Pet Per I ,4 weight cent cent cent F0 Zn Pb .17'0 Zn" Pb'. .Head 100.0 7.60 11.40 0.07 1000 100.0 100.0 Pb 11.00000"; 10.2 6.8 15.8 41.4; 0.1 14. 74,4 Zn c0nc. 14.1 5.3 50.0 610 -1l.7 01.5 1510 Zn middling 8.7 3.8 20.0. 3.0, 15.8 174 4.0 Tniling 07.0 1.2 1,2 0.5 03.4- 1.0 .00 from"-.. 10.0.0 00. 0 100.0 100.0

. 4 8. 1000 grams of ore werefgrou'nd to the desired fineness ln a-ball 111111 with 1.0 lb. of

chlorine, 0.5 lb. of zinc sulfate, and 43.0 lbs.

'7 of sodium bicarbonate per ton, of ore, to.-

. diluted as before and passed.

, allowin froduct gether with 500 cc. of water.

A toa flotation machinefoil added, and the the addition of 0,4 lb.- of Barrett-N0, 4- oil and 0.105 ofjsteamfdistilled pine oil, 'afroth" f. V I liar cent recovery oltotol I'll. i'c

31000. 100:0 11a 1 g 22.0 19.2 i ..74;-4 0&0 as

This se arg itii ma' amide time the methods specified inthe. separation 0f lead and zinc, subject, of'course, to the same I restriction ,i. -e.,tl re. natl 1re' of the ore and ball mill with 2.0 lbs, of caustic soda, 1.0 lb.-'

jco'nclition, of the ore' pulp.

- 9'; 1000 grams of: ore (t lfrough 10 mesh) 1 were ground to"'the 'necessary fineness in a I ,of chlorine-per ton of. ore, and. 500 cc. of

water; I The ulp'w-as diluted as ,beforeand passed to: a otation machine, andupon the addition of a suitable oil, a frothcontaining ('blende) formed immediately, v resulted in the removal of a considerable porti0nof-the-zinc Without the use of Q used that any result obtained. I I Theg 'p'articular alkaline agent employed ,The-pulp was froth contain-- "ing the copper removed; to the pulp in the :machine, 1.0-lb, of, caustic 'soda'was added, a time treatment 7 of two minutes- (equiva enttd 'passa through launders and elevator" in -practica operation), and upon the cofpperjwasformed and removed,- the Iron,

combined with the copper, as in chal'copyrite and bornite,

cannot be separated from the copper;

Thehigh percentage of iron in the; copper concentrate is "due .to :this

fact.

, I In th practice of the: invention as illustrated by the specific examples, the halogen will vary, but it must be borne in mind member of this group-bromine, chlorine, or iodine-army be substituted for, the one usedfand substantially the' same is detormined by the nature of, the ore-in some ores acertain' alkaline agent willgive better results than another, andvice-versa.

a-lead product low in' z nc. I After an ore has been treated with a sufor the-most part, remainingfin the 05 'In treatingsome ores, it is adyantageous .,to :use zinc sulfate in combination with .the otherv reagentsas it aid greatly in making ficient' amount of a halogen and the sep'ara-f tion of lead sulfide or copper sulfide from zinc sulfide is obtained, we have found that a" further "addition. of a' halogen (the 'quan tity varying with, the ore and "pulp condi tion) to the pulp,

either with" or without" I analkali, will cause the 'immediateforma- I tion of a froth high in zinc, and leave the I ':iron in [the tailing; i; e.', inhibit the iron from. floating. In. some cases a clean. tail- ;ing may be made without the further use'of oil; in others an.oil-is,required. w I I I I t-'w'ill be noted, however, that the 'sep'ara tion, of lead sulfide or lropper (sulfide, orboth, from zinc sulfide may p v of the ways previously mentioned, and that the'separation; of zinc sulfide from iron sulfide mayf-be abcomplished byatlie use of abe made inany .zalkalinea eiit such-as anv alkali, alkaline salt, ttlkllll earth saltj or hydroxide. .The

amount of .the halogen used is dependent uponythe particular ore or metallurgical product .to be 'treatedfia'certain amount.

being necessary-for the separation of lead or copper sulfide from. zin'c' sulfide, and a cer-.

zin sulfide from iron sulfide.

.tain further amount forthe separation ,of

Our invention is applicableto ores, concentrates, t'ailin'gs, and other metallurg'icalproducts containing lead, copper, zinc, or lIOI1 sulfides in any comblnation, for which the term ore is used throughout this sepc1fi= cation and the appended claims.

The addition of the halogens to ore pulps may be made in several ways; bromine, a liquid. and iodine, a solid, may be added directly to pulp in a ball-mill, or in a tank at any desired point chlorine, a gas. may be added as chlorine water, or the pulp may be chlorinated at any point in the flow.

It is, sometimes desirable to secure an iron concentrate, since in many ores gold and silver occur. with the iron, and may be recovered in this way. In floating the iron after removal of zinc, heavy oils, such as an acid sludge, coal tar creosote, or pine tar, either alone or in combination, are ellective. It is understood, of course, that other oils or oil combinations may be used advantageously in this connection,

\Vhile it seems probable from our investigations that fluorine behaves like the other halogens with respeet to its differential action on sulfide minerals, the practical difliculties in using fluorine in a flotation mill are so great that we now consider fluorme' 'nnpractlcable 1n the commercial practice of the invention and on this account and to this extent we exclude fluorine.

\Ve claim:

, 1. The process of concentrating by froth- .flotation an ore containing sulfides ot-lead,

copper, zinc, and iron, which comprises treating the ore with a halogen 1n such amountv as will substantially inhibit the flotation of zinc and iron sulfides, and subjecting the so treated ore-to a flotation 0 eration in which the lead and copper sul des are in large part recovered in the resulting froth and the flotation of the zinc and iron sulfides is in large part inhibited.

2. The process of concentrating by frothvflotation an ore containing sulfides of lead,

zinc, and iron, which comprises treating the ore with a halogen in such amount as will substantially inhibit the flotation of zinc and iron sulfides, and subjecting the so treated ore to a flotation operation in which the lead sulfide is in large part recovered in the resulting froth and the flotation of the zinc and iron sulfides is in large part inhibited. A v

3. The process of concentrating by frothflotation an ore containing sulfides of leadv and zinc, which comprises treating the ore with a halogen in such amount as will subv stantiallyfinhibit the flotation" of zinc sulfide, and subjecting the so treated ore to a flotation operation in which the lead sulfide is in large part recovered in the result ing froth and the flotation of: the zinc sulfide is in large part inhibited.

4. The process of concentrating by frothflotation an ore containing sulfides of copper, zinc, and iron, which comprises treating the orewith a halogen in such amount as 'will substantially inhibit the flotation of zinc and iron sulfides, and sub jccting the so treated ore to a flotation operation in which the copper sulfide is in large part recovered in the resulting froth and thcflota-tion of'the zinc and iron'sulfides is in large part inhibited.

5. The process-ofconcentrating b frothflotation an ore containing sulfides 0 copper and zinc, which comprises treating the ore with a halogen in such amount as will substantially inhibit the flotation of zinc sulfide, and subjecting the so treated ore to a flotation operation in which the copper sulfide is .in largepart recovered in the re suiting trot-h and the flotation of the zinc sulfide; is in large part inhibited.

6. The process of concentrating by frothflotation an'ore containing sulfides of copper and iron, which comprises treating the ore with a halogen in amount approximating one pound per ton of ore, and subjecting the so treated ore to a flotation operation in which the copper sulfide is in large part recovered in the resulting froth and the flotation of the iron sulfide is in large part inhibited.

7 The process of concentrating by frothflotation an ore containing sulfidesof zinc and iron, which comprises treating the ore with a halogen in mount up roximating one 'pound per tonof ore, an subjecting the so treated'ore toa flotation operation in. which the zinc sulfide is in large part recovered in the resulting froth and the flotation of the iron sulfide is in large part inhibited; i

8. The process of concentratin by frothflotation an ore containing 'sulfi es of lead,

treating the ore in a non-acid pulp with a halogen in such amount as will substantially inhibit the flotation of zinc and iron sulfides, and subjecting the so treated ore to a flotation operation in which the sulfidesof lead and copper are in large part recovered in the resulting froth and the flotation of the zinc and iron sulfides is in large part inhibited.

9. The process of concentrating by froth flotation an ore containing sulfides of lead,

.zinc, and iron, which comprises treating the ore in a non-acid pulp with a halogen in such amount as will 'substantiall inhibit the flotation of zinc and iron sul des, and subjecting the so treated ore to a flotation; operation in which the sulfide of lead is in large part recovered in the resultingfroth and the flotation of the zinc and iron sulfides is in large part inhibited.

10. The process of concentratin "by frothflotation an ore containing sulfi es of lead and zinc, which comprises treating theore amount as will $11 the sulfide of lead'is jinlarge part recovered.

in the resulting 'froth'and the flotation-"of the zinc sulfideis in large part" inhibited. 11. The process of flotation an ore containing sulfi es of cophibit the flotation 4 approximating one 85 I froth and t e flotation of the is in large part inhibited.

7 is in large part recovered hibited. I

.ing froth and iron sulfides is in l in a non-acid pulp-with aflotation an ore and subjecting th per, zinc, and iron, Which comprises treating the ore-in a non-acid pulp with .a'halogen in such, amount as will substantially-inofzinc and iron sulfides, and subjecting .theso treated ore to a Vflota tion operation in which the sulfidejbf cop-- per is in large part recover'edi'n the results the fletation' of thejzinci andarge' part inhibited. I 12. The process. of concentrating flotation an ore containi which comprises treatingthe ore halogen in such" amount as will substantially inhibit the flo tation of zinc sulfide, and subjecting the. so treated ore to a 'flotationoperation inwhich copper is in'large part recovered in the resultin "froth andthe flotation of the zinc sulh d inhibited. 1 13. The

e slln large -part 1 process of concentrating b froth;

containing sulfides of copper and iron, which comprises treating theore in a non-acid pulp with a halogen in amount I pound per. ton of ore, and subjecting the so treated ore' to a flotation' operation in which the sulfide of copper is in large art recovered in't'he resulting iron sulfide The process of concentrating by frothflotation and iron, which comprises-treating the ore in a non-acidpulp with a halogen in amount" approximating one pound per ton of 10m,-

e so treated ore to a flotation operationin 'which the sulfide of zinc. in the resulting froth andthe flotation of the iron sulfide is in large partinhibited;

5. The process of concentrating by froth flotation an ore containingsulfides of lead," copper, zinc, and. iron, which comprises treating the ore with a halogen and an alkaline agent in such amounts as will substantially inhibit the flotation of zinc and iron sulfides, and subjecting the so treated ore, tov a flotation operation in {which the lead and copper sulfides are in large par recovered in the resulting froth and the fio gatlOIl of the zinc and iron sulfides is in large part in- 16. The process of concentrating by froth flotation an ore containing sulfides of lead, zinc, and iron, which comprises treating the ore with a halogenand an alkaline agent amounts as will inhibited," frothagent flotation an ore containin an ore containing sulfides of f'Zinc ofzinc, and iron epart'. recovered,lathe-resultingfroth andt e flotation of'the-zinc and'ironsol-- fides-is in; large-part inhibited; T

i- 17. .'I .h"e flotation an oreand zinc, which' comprises treating the ore with a halogen and an alkaline' substantially in ibit the flotation of zinc sulphide, and-subjecting. the sof'treated ore to a flotation operation in whichthelead'sulfide is .in large part re-v covered in the resulting froth and the flo tat-ion. of-fthezinc sulphide is in large part 18. Theiprocess of concentratin' by froth flotation an ore 'c'ontainin sulphicias of copper, zinc], and iron, whic comprisestreating the orewith ,a'halogenjand an alkaline in. suchamounts; as will substantially inhibit thei-flotationof zinc and; iron sulfides, andisubjecting the so treated ore to a flotation operation in which the copper sulfide" isinqlargefpart recovered inthe resulting froth and the: flotation of the v sulphides ,is' in large'part inhibited.

- 19; The process of con'centrating by froth g sulfides of copper and zinc, Yv'vhich comprises'treating the ore with-a hal'ogen and a'n alkal amounts a'swill substantially inhibit the flotation ofzinc sulphide, and subjecting the so treated ore to a flotation operation in which zinc and iron as will substantially in sulfides, Q. so treated ore'toja fiota-' tion*operationin which thelead sulfide is."

in Ian 10 process of concentrating by froth containing sulfides of lead '70 ent, in such 1 ine agent in such eredin the resulting froth and the flotation of the zinc sulphideis inlarge part inhibited 20. The process of concentrating by froth flotation an ore containing sulphides of 0011- per-andironfwhi'ch comprises treating the ore with ahalogen and an alkaline agent n such 'amountsas will substantially inhibit the flotation ofiron sulphide, and subjecting flotation'operation in the so treated ore to a whichthe-copper sulphideis inlarge partrecovered in the resultingfroth .and' the flotation "of the-iron sulfide is in-la'rge part inhibitedr f 1 A 21; The process of concentrating by froth flotation an ore containing sulfides of zinc and iron", which comprises treating'the ore with a ialogen and 'an alkaline agent in such amounts as will substantially inhibit the flotation of iron sulphide, and subjecting the so treated ore to a flotation operation in which the zinc sulphide i covered in the resulting froth and the flo 'tation of the iron sulphide inlargepart inhibited. I

22 The process of concentrating by froth flotation an ore containing sulphides of lead and zinc, which comprises treating the ore with'a halogen, an alkaline agent, and zinc s'in large part rev '-cove'red in the resulting sulphate andthereby inhibiting in large art the flotation of zinc sulphide in the oli ing flotation operation, and subjecting the s'o'treated ore to a flotation operation in which the lead sulphideis in large part reiroth and the flotation of thezinc sulfide is in large part inhibited.

flotation an ore containing sul zinc, and 'iron,

23. The process of concentrating by froth hides of lead, which comprises subjecting the ore. in the form of an ore pulp to the action of a halogen in such amount as will substantially inhibit the flotation of zinc and iron sulfides, subjecting the sotre'atcd ore pulp to a flotation operation and thereby ,efl'ecting in large part the flotation of the lead sulphide while inhibiting in large part the flotation of the. zinc and iron sulfides,

treating the remaining ore pulp with a halo- 7 gen in'such amount will substantially 111-- hibit the flotation of iron sulfide, and subjecting the treated remaining ore pulp to another flotation operation in 'which'the zinc sulfide is in large part.

recovered in the resulting froth.

24, The process of concentrating byfroth flotation an ore containing sulfides of copper, zinc, and iron, which comprises subjecting .the ore in the iron sulfides, subjecting the so treated ore pulp 'to a flotation operation and thereby efiecting in large part the flotation of the copper I sulphide while inhibiting in large vpart the flotation, of'the zinc and iron sul" tides, treating the remaining ore pulp with a halogen in such amount as will substantially inhibit the flotation of iron sulfide, and subpulp to another flotation operation in which the zinc sulphide is in large part recovered in the resulting froth.

line agent 7 toanother operation,

to a flotation operation in which the copper sulfideis in large partrecovered in the 'resulting 'frothj'and the flotation of the zinc formof au ore pulp to the action of' a halogen 'insuch amoun't'as will substantially inhibit the flotation of zinc and flotation an ores-containing sulfides of lead; zinc, and iron, which the ore in the form of an ore' pulp to the action of a halogen in such amount as will substantially inhibit, the flotation of zinc and iron sulfides, subjecting the so treated ore to a flotation o ration and thereby effecting in large part t e flotation of the lead sulfide while inhibiting in large part the flotation of the zinc and iron sulfides, treating the remaining ore pulp in'such amounts as will substantially inhibit the flotation of iron sulfide, and subjecting the so treatedremaining ore pulp froth. I 26. T

zinc, and-"imn, which comprises subjecting the ore in'the form of an ore pulp to the action of a halogen in such amount as will inhibit in lar e part/the flotation of the zinc and iron sul subjecting the m-treated ore pulp and iron sulfides is in large part inhibited,

treatiug'the remaming'ore pulp with a halogenand an alkaline. agent and thereb hibiting in large part the flotation 0 iron sulfide in the following flotation operation, and subjecting the so-treated remain mg ore pulp to another flotation operation in which the zincsulfide is in large part reflotation operation in which the' zinc sulfide is in'large part recovered in the 4 resulting Q e process of'concentrating by flotation an' 'ore "containing: sulfides of eopper,

comprises subjecting with a halogen and-an alkades in the following flotation. Y

the I I 

